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DEPARTMENT OF COMMERCE AND LABOR 
BUREAU OF nSHERIES 

GEORGE M. BOWERS, Commisaionet 



CULTURE OF THE MONTANA 
GRAYLING 



Bureau of Fisheries Document No. 628 




WASHINGTON 

GOVERNMENT PRINTING OFFICE 

1907 



DEPARTMENT OF COMMERCE AND LABOR 
BUREAU OF FISHERIES 

GEORGE M. BOWERS. Commissioner 



CULTURE OF THE MONTANA 
GRAYLING 



Bureau of Fisheries Document No. 628 



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WASHINGTON 

GOVERNMENT PRINTING OFFICE 
1907 



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CULTURI OF THE MONTANA GRAYLING 

By James A. Henshall 

Superintendent U. S. Fisheries Station at Bozenian, Montana 



Bureau of Fisheries Document No. 628 



CULTURE OF THE MONTANA GRAYLING. 



By James Alexander Henshall, 
Superintendent U. S. Fisheries Station at Brjzeman, Mont. 



CHARACTERIZATION OF THE SPECIES. 

The Montana grayling originalh^ existed only in the tributaries 
of the Missouri River above Great Falls, and was first noticed by 
Lewis and Clark, during their remarkable journey to the Pacific coast. 
They described it from fish taken near the headwaters of the Jeffer- 
son River, but did not name it, alluding to it as a new kind of white 
or silvery trout. It was rediscovered by James W. Milner, of the 
U. S. Fish Commission, in 1872, in a tributary of the Missouri near 
Camp Baker, Montana. He described it, and named it Thymallus rnon- 
tanus. At iii'st it was said to be a variety of the Michigan grayling, 
but it is now given specific rank. In its afhnities it is really more 
nearly related to the Arctic grayling (T. signifer), as may be seen from 
the following characterizations: 

Specific Characters of the Graylings. 





.c 


^ 




c 








U,S3 


>> 


Species. 


c 

a 


6jO 

C 


c3 










r3 M) 


o 

c 
o 




■^ 




n 


~.q 


y 


s 


03 


■^ C 


m 




M 


n 








o 


o 
Q 


bJJta 


O 


T. signifer 


5h 


41 


3 


2A 


S-SS to 90-1 1 


12 below angle 


20-24 


3i 


Anterior. 


T. tricolor 





oh 


4 


21 


93-98 


7+12 


21-22 


5i 


Posterior. 


T. montanus 


5 


4i 


3.V 


3 


S-82 to 8^10 


5+12 


18-21 


4i 


Anterior. 



a To orbit. 



Description. — From the examination of a large series of fresh speci- 
mens the following detailed description of the Montana grayling 
may be given: 

Head moderate, subconic, its length contained 5 timQS- in length 
of body, curving regularly from snout to dorsal line, and continuous 
with it. Mouth moderate, oblique, terminal, the maxillary extend- 
ing to the anterior border of the eye, its length 3 times in head; jaws 
equal. Eye large, 3* in head, nearly equal to interorbital space, 
and longer than snout, the pupil pyriform or pear-shaped, with the 
apex anterior. Teeth feeble, sparse, and uniform in size; on jaws, 

3 



4 CULTURE OF THE MONTANA. GRAYLING. 

vomer, and i)alatines; none on tongue. Gill rakers 5 + 12. Scales 
moderate, 82 to 85 along lateral line, with 8 rows above and 10 rows 
below; lateral line nearly straight, curving upward slightly toward 
the head. Dorsal fin long and high, the height greater than depth 
of body; 18 to 21 rays. Caudal fin strongly forked. Coloration: 
Back i)luish-gray with purplish reflections; sides and gill-covers 
hghter, with purple and silvery reflections, beautifully iridescent; 
scales with a pearly luster; belly pure white; a few V-shaped black 
spots between the head and middle of dorsal fin, but none posteriorly; 
two ol)long, bluish black blotches in cleft between opercle and 
branchiostegals, more pronounced in the male; a line on upper border 
of belly fi'om ventral to pectoral fins, dark and heavy in the male, 
very faint in female. Dorsal fin edged with a red or rosy border; 
four to seven vertical rows of red or rosy roundish spots, ocellated 
with white between the dorsal ra^^s; dark lilotches fornung lines 
between the rows of red spots. Ventral fins with three rose-colored, 
branching stripes along the rays, darker between. Pectoral and anal 
fins plain, with dark border. 

Origin. — It is very probable that the Arctic grayling was the parent 
stock fi'om winch the Michigan and ]\Iontana graylings descended; 
and fi"om the fact that the habitats of the tlu'ee species are so 
widely separated, it is not unreasonable to suppose that the IMichigan 
and ^lontana forms were conveyed thence fi'om the Ait tic regions 
during the Glacial period. This theory is strengthened l)y the fact 
that Elk Lake, a half nule from the ]\Iontana grayling station, is 
abundantly inhabited by both grayling and the lake trout {Cris- 
tlvomer nainaycush), \yhich. latter fish is found nowhere else west of 
Lake Michigan. 

Gume and food qu<dities. — The ISIontana grayling is a most grace- 
fid and beautiful fish, whose dainty and lovely proportions and 
exquisite coloration nuist be viewed fresh from its native waters 
to be appi-eciatcd properly. As a food fish it is fully as good as the 
trout, and \o my taste better. Its flesh is firm and flaky, very white, 
and of a delicate flavor, as might be expected. As a game fish it is 
the equal of its congener, the red-throat trout, and when hooked 
breaks ^\ater re})eatedly in its eftorts to escape, winch the trout 
seldom does. It tak(>s the artificial fly eagerly, and if missed at the 
fij'st cast will rise again and again from the tlepths of the pool, whereas 
the trout will seldom rise the second time to the same fly without 
a rest. 

Habits. — The Montana grayling prefers swift, clear streams of pure 
water, with gravelly or sandy bottom. It is quite gregarious, lying 
in schools in tlie deeper pools, in plain sight, and not, like the trout, 
concealed under bushes or overhanging banks. In search of food, 
\\ hich consists principally of insects and their larvte, it occasionally 



CULTURE OF THE MONTANA GRAYLING. 5 

extends its range to streams strewn with bowlders and broken rocks. 
The fry subsists on minute crustaceans, as Entomostraca, and for 
seizing the minute organisms is furnished, hke the lake wliitefish 
fry, w4th two sharp, retrorse teeth in the upper jaw. 

Unlike the Rocky Alountain trout {Salmo clarkii), but like the 
salmon, the grayling will go long distances, if necessary, to find suita- 
ble spawning grounds. The auxiliary grayling station of the Bureau 
of Fisheries is on Elk Creek, one of the feeders of Red Rock Lake, at 
the head of the Jefferson River. At the beginning of the breeding 
season many grayling go up the Jefferson, through Beaverhead and 
Red Rock rivers, to Red Rock Lake, 14 miles in length, and through the 
lake to the inlets at its head, iifter spawning they return through the 
lake to the streams below, none stopping in the lake, as it is unsuit- 
able, being shallow and with an alkali bottom. At spawning time 
Elk Creek is fairly alive with grayling on the gravelly shallows, 
where their large and beautifid dorsal fins are to be seen waving like 
so many banners, clear of the water, in the manner of shark fins on 
a fiood tide. In the North Fork of the Madison River, where the 
water is comparatively warm, coming from the Firehole River in 
Yellowstone Park, the grayling spawns a month earlier than in other 
waters of Montana. 

METHOD OF ARTIFICIAL PROPACJATION. 

Strip [y'mg and incuhation. — One fish produces from 2,000 to 4,000 
eggs, which are about one-seventh of an inch in diameter, running 
from 750 to 850 in nimiber to a fluid ounce. The eggs in the ripe 
fish lie loose in the abdominal cavity, as in the trout, and the fish 
is quite as easily stripped — the eggs perhaps a little harder to start, 
but afterward flowing freely. They are fertilized by the dry proc- 
ess, and fully 95 per cent are fecundated. They require much more 
washing than trout eggs, to free them of a glutinotis substance that 
otherwise would cause them to bunch. , 

When fij"st extruded the eggs are of a rich aml^er color, owing to 
the presence of a large oil drop, which renders them almost semi- 
buoyant; but after a few days of incubation they become hyaline or 
glass color, and as clear as crystal. It is imperative that they be 
eyed in hatching jars with a good pressure of water, to obviate all 
danger from btmching and fungus. If the}" are placed on ordinary 
fiat trays, touching each other, and exposed to a lateral current of 
water, they adhere in bimches, fimgus appears, and much labor is 
entailed in picking, ending in a great loss of eggs. After the eye- 
spots show the eggs may be placed on the ordinary hatching tra}^, 
being then much hea-sder and not likely to float oft'. The embryo 
becomes very active before the eye-spot appears, which occurs in 
about a week or ten days at a temperature of 50° F. Incubation 



6 CULTURE OF THE MONTANA GRAYLING. 

is then coiiiplete witliin two weeks. If the water is much colder the 
period will be several days longer. 

The fry is hatched with a very small yolk sac, smaller than the 
egg, and this sac is absorbed in a week or ten days, the fry then 
becoming a free swimming animal about half an inch long, quite 
slender and delicate, resembling somewhat the fry of whitefish or 
shad. 

Tmnsportation of eggs. — The usual method of packing and shipping 
salmon and trout eggs will not answer for grayling eggs. They will 
not bear crowding or pressure, and must be kept at a ver}^ low tem- 
perature. The period of incubation being so brief, there is a possibility 
of their hatching in transit if they are several days en route and the 
temperature rises al)ove 42°. This was demonstrated the first sea- 
son at the Bozeman station, when the eggs were shipped in ordi- 
nary trout-egg cases, and even with the precaution of pacldng ice 
with the moss about the stack of egg trays. Before the next season 
I devised the refrigerator case, with double wall, by means of which 
the temperature can be kept at 40° or l)elow for any length of 
time if properly re-iced, and the eggs will reach their destination in 
excellent condi tion . 

For the better aeration of the eggs was devised also a special egg 
tray but one-half inch in depth, with cheese-cloth bottom. No moss 
is placed over the eggs on the tray, for, as before stated, they will 
not bear any pressure, and a piece of mosquito netting is all that is 
required to keep them in position. A space of 2^ to 3 inches is left 
between the inner wall of the refrigerator case and the stack of egg 
trays, and this, as well as the hopper on top of the trays, should be 
kept constantly tilled with ice. The hopper has perpendicular sides 
instead of the flaring sides usual in trout-egg cases, to facilitate 
re-icing of the s})ace surrounding the stack of trays during transporta- 
tion. The frames of tlie egg trays are 1 inch wide, so that when 
placed in a stack they form a wall 1 inch thick to separate the eggs 
from the ice, and there is no possible danger of freezing the eggs; 
this was demonstrated by experiment. For grayling egg-case labels 
the precaution "Do not expose to freezing temperature" is always 
erased, as unnecessary, and moreover, useless when considered in 
connection with the notice to express messengers to re-ice en route 
and to keep as cold as possible. 

Feeding ihe fry. — If stream water containing the minute crusta- 
ceans that furnish suitable food for the fry, as most streams do, can be 
supplied to the fry in the hatchery from the first, no artificial feeding 
will be necessary for a month or six weeks. If, however, only spring 
water can be had, great care must be exercised and the ingenuity and 
intelligence of the fish-culturist brought into requisition to discover 
the best means of feeding. It was found that fresh blood supplied 



CULTURE OF THE MONTANA GRAYLING. 7 

before the yolk sac is entirely a]:)sorbed answers a o;ood purpose. 
Liver emulsion rendered as fluid as possible, and then strained through 
ordinary muslin, will serve to tide the fry over the precarious stage 
until they are a month or six weeks old, when they can be fed the 
same as trout fry; but during the first stages they must be watched 
closely and fed much more frequently than trout fry. If fresh blood 
can be procured and stirred until it becomes a homogeneous fluid, 
free from clots, it can advantageously be supplied either straight or 
mixed with the strained liver emulsion. But, owing to the very 
small size of the grayling fry, artificial feeding is under all circum- 
stances cjuite a problem. At the Bozeman station they have been 
reared to maturity in the manner mentioned with a loss of from 50 to 
70 per cent; and the mature iish have been, stripped and the eggs 
hatched and fry planted. This has been done several seasons, though 
only a portion of the females yielded good eggs and many males were 
not in good breeding condition, possibly from a lack of their natural 
food and from being kept in spring water. 

The fry should be transferred to shallow, sunny nursery ponds with 
a good current of stream water, of a higher temj^erature than spring 
water, if possible — say from 55° to 60°. They l)egin to forage for their 
natural food as soon as placed in the pond, and are exceedingly active 
and industrious. If the w^ater is found to contain an abundance of 
their natural food, which can be determined by examination with 
the microscope, they will do well. In addition, however, it is well 
to feed the fry at least six times a day for several weeks; otherwise 
they may begin to eat each other, being very cannibalistic. Owing 
to this tendency it is, moreover, advisable to begin with two or three 
times as many fry as it is desired to rear. 

Output of the government grayling hatchery. — The following table is 
a statistical resume of the results of grayling propagation by the U. S. 
Bureau of Fisheries in the last decade. 

Output op Grayling from the IT. S. Fisheries St.\tion at Bozeman. Mont., 

1898-1907. 



Year. 


Eggs 
collected. 


Eggs 
shipped to 

other 
stations. 


Fry and 
fingerlings 
distributed. 


Adults and 
yearlings 
distrib- 
uted. 


1898 


2, .506, 200 
5,735,000 
3,687,000 
2, 400, 000 
4,46.3,000 
3,045,000 
3,247,800 
1,010,000 
1,650,000 
2,370,000 


115,000 
380, 000 
814,000 
390, 000 
1,4.55,000 
645,000 
494,000 
400, 000 
642,000 
2.')0,000 


1,. 500, 000 

4,567,000 

2,449,718 

1,453,461 

1,130,333 

974,114 

2,692.200 

400, 000 

800,000 

1,376,200 




1899 




1900 


if), 666 
11 7''1 


1901 


1902 


18,000 
368 


1903 


1904 


905 


1905....: 




1906 




1907 








Total _ 


30,114,000 


5,585,000 


17,343,026 


40, 3S4 



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LIBRftRY OF CONGRESS 



002 854 171 5 



